Eleven days after its worst loss of the season, St. John’s produced one of its most complete performances.

The opponent — Big East cellar-dweller Creighton — was the same. The Red Storm sure weren’t.

Look no further than Rysheed Jordan for the 21-point improvement, from a 77-74 loss Jan. 28 in Omaha, Neb., when a right knee injury limited him to just seven minutes, to Saturday’s 84-66 victory at the Garden.

“He was without question the best player on the floor today,” Creighton coach Greg McDermott said.

Jordan, an uber-talented but enigmatic sophomore guard from Philadelphia, scored a career-high 25 points, hitting a personal best six 3-point attempts to key the Johnnies rout, while also grabbed six rebounds and dished four assists. He was at his scintillating best in the first half, scoring 19 points as the Johnnies (15-8, 4-6 Big East) threatened to run Creighton (11-14, 2-10) out of the building, shooting a blistering 66 percent from the field and producing 52 points, the Red Storm’s most in a half this year.

“Last game, [Creighton] triangle-and-two’d us, they tried to do it again today. I just was like, be over-aggressive,” D’Angelo Harrison said of Jordan. “He was on today. It’s hard to guard him when he’s hitting shots and dominating the ball. We fed off his energy.”

Harrison, looking healthier than he has in weeks, added 21 points, 10 rebounds, six assists and no turnovers, while Sir’Dominic Pointer chipped in 10 points, seven rebounds and eight blocks. Chris Obekpa only played six seconds — he came off the bench as a disciplinary measure for his Flagrant 2 elbow in Tuesday’s loss to Butler — and suffered a sprained right ankle in his brief appearance early in the second half. He is probable to play Wednesday against DePaul.

St. John’s actually benefited from Obekpa’s absence, going with a team of guards to combat Creighton’s deadly 3-point attack. In the first matchup, Creighton hit 13 3-pointers and forward Toby Hegner was particularly effective from beyond the arc against Obekpa. The Bluejays made just of 5 of 22 this time around.

“They were able to switch on everything because we didn’t take advantage of them in the post,” McDermott said. “It worked into their hands.”

It’s been a roller-coaster season for the 6-foot-4 Jordan. He is averaging 13.6 points per game — eighth-most in the Big East — but also has committed more turnovers than assists. He also has missed two games — one because of the flu and another after taking a four-day leave of absence from the program.

There was the knee injury in the Creighton game. He came off the bench in a Jan. 31 win against Providence, the result of coach Steve Lavin disciplining him for a homophobic tweet. He has not been made available to the media — Jordan has yet to speak to reporters since arriving at St. John’s — because Lavin wants him to focus on basketball and academics.

At this point, St. John’s isn’t going to take a chance. It needs the Jordan it saw Saturday to show up consistently. After all, it was around this time last year when Jordan began to play his best ball, and the Johnnies came together at the same time, closing the Big East regular season with seven wins in nine games. A similar run likely would result in an NCAA Tournament berth.

“He’s returning to the form of where he was last year, but even better because he’s got more experience now than he had a year ago,” Lavin said. “Today is a step in the right direction.

“In high school, this was a kid I saw get 50, 60 points in a game, torch the nets from all angles. He’s someone that can score in a variety of ways. After that tough stretch of health and family issues, he’s had three, four weeks of good practices. He’s beginning to find his stride. We didn’t have him against Creighton. He clearly made a difference and he would’ve made a big difference if we had him [in the first game].”